Vibrator



J. C. FIELD.

VIBRA TOR.

APPLICATION FILED DEC.29, 1919.

1,368,916. Patented Feb. 15,1921.

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UNITED STATES PATENT OFFICE.

JOSEPH C. FIELD, OF ORANGE, NEW JERSEY, AS SIGN OR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF YORK.

VIBRATOR.

Application filed December 29, 1919. Serial No. 347,918.

To all whom it may canoe m:

Be it known that I, JOSEPH C. FIELD, a citizen of the United States, residing at Oran e, in the county of Essex, State of New ersey, have invented certain new and useful Improvements in Vibrators, of which.

the following is a full, clear, concise, and exact description. I c

This invention relates in general to v1- brators and more particularly to a vibrator suitable for providing a high frequency tone for signal purposes or for interrupting an independent circuit at a high frequency.

In telegraph and telephone systems it is often des1rable to place a high frequency tone upon a line for signaling purposes and 'in connection with portable sets for use in field service, it is necessary'that such a vibrator not only be very sensitive in order to insure a low battery consumption but it also must be sufliciently rugged to withstand the severe service conditions to which it may be subjected without requiring change in adjustment.

It is therefore the object of the present invention to provide a vibrator especially adapted for portable sets, one which will cause a very small current drain on the operating battery, will be reliable in operation and cheap to manufacture.

To attain this object and in accordance with a feature of the invention, there is provided a vibrator in which a plurality of transmitter buttons are placed inoperable relation upon a single armature, one of these buttons functionin in conjunction with an electromagnetic evice for causing the operation of the armature and the other button being arranged to place a tone u on the line. In accordance with another eature of the invention, the armature is given a slight curvatureso as to permit, obtaining a more delicate adjustment.- These and other features of the invention will be more clearly understood by referring to the accompanying drawings, in which Figure 1 is a,plan view of a vibrator embodying this invention, suitably mounted upon an insulating plate and provided with the necessary line terminals Fig. 2 is a view partly in section of the structure shown in Fig. 1; Fig. 3 is a view showing the manner in which the transmitter buttons are secured to the armature; and Fig. 4 is a diagrammatic view of the circuit arrangement.

phone transmitters.

Specification of Letters Patent. Patented Feb. 15, 1921.

Referring to the drawing, there is prov-ided a mounting plate 5 of insulating mater al to which a circular plate 6 of brassis rigidly secured. The perimeter of plate 6 is provided with threads to engage similar threads in a cylindrical housing 7 which functions to completely inclose the vibrator and protect it from dust and injury. Mounted upon the plate 6 and secured there to by the screws 8-8 is a substantially U- shaped member 9. Upon one of,the upright portions of member 9 are mounted transmitter buttons 10 and 11 which, are similar to the type commonly used in tele- The stem portions of these buttons pass through suitable perforations in the member 9 but are insulated therefrom by means of insulating washers 12-12 of hard rubber or other suitable material and insulating bushings which are not shown in the drawing. These buttons are held in place by means of the nuts 13-13 ,which engage the threaded stems of the transmitter buttons. The front electrodes of buttons 10 and 11 are provided with threaded stems 14 and 15 respectively fitted with suitable nuts 16 which serve to position the armature 17. This armature,fwhich is provided with suitable perforations arranged to permit its free movement over the stems 14 and 15, is provided with a bowed spring member 18 which is riveted or otherwise secured to the armature at its center point. The free ends of this spring member are slotted to straddle the stems 14 and 15 and bear against the members 19 and 20 with suflicient force to position the armature 17 against-the nuts 16-16. The armature is given a slight curvature, as shown, so as to present a slightly convex surface to the nuts 16-16.

Upon the other up-right portion of the member 9 are secured a permanent magnet 22 substantially circular in shape and inwardly extending electromagnetic coils 23-23. The cores 24-24 of these coils are provided with right angled extensions which in turn are slotted to permit their being'secured in place by means of the screws 25-25 and nuts 26-26 which secure the permanent magnet in position. For adjusting purposes, there is provided a screw 27 the head of which shoulders against one of the upright portions of member 9 while the end is adapted to engage suitable threads 1n the other lip-right portion of member 9. By turning this screw, it is possible to draw these portions closer together and thereby reduce the air-gap between the armature l7 and the inwardly extending ends of cores The mounting plate is provided with suitable terminal punchings 30, 31, 32 and 33 which are mounted outside of the housing 7 and with conductors which extend from these terminals through suitable slots in the mounting plate 5. From terminal 33. a conductor 34 is brought through suitably bushed perforations in plate 6 through periterations in member 9 and to one terminal i" the coils 23, the windings or" which are connected in series. The other terminal of the coils 23 is connected by suitable conductor 35 to a terminal 36 in direct electrical connection with the back electrode of armature button 10. From this same terminal a conductor 37 extends downwardly through a suitable bushing in the plate 6 and runs along a slot in theniounting plate 5 to the terminal 30, to which it is soldered. From the terminal 32, a conductor 33 is led through a slot in the mounting plate 5 and is brought up through a suitably bushed hole in the plate 6, then passing through perforations in the up-right portion of member 9 and to terminal 40 which is secured to the plate member 9 by one of the mounting screws 8. From this terminal a flexible conductor extends to tie front electrode member which is electrically joined to member 19 by means of the spring 18. From the terminal 31, conductor 4:2 is carried through a slot in the base 5 to the terminal il which is indirect electrical contact with the back electrode of button 11.

In operation, the battery 45 in series with a key 46 is connected directly across the terminals 32 the line wires L and L upon which it is desired to place the sig nal current are connected respectively to terminals 31 and 33. In order to provide more steady operation of the vibrator, a condenser i? is preferably connected across the terminals and 33. Upon closing the key it current flows from the positive pole of the battery 45 which is connected to the ter minal 33 through the winding of the coils 23-23, the transmitter button 10, spring 18,

the front electrode of button 11, terminal thence through the conductor 38 to teri 32, to which the negative pole of the "y is connected. Upon the flow of currough the coils 23-423, the armature 1"? is attracted, thereby increasing the resistance of the transmitter button 10 and consequently decreasing amount of currentv through the c cuit. strength *1 curruit .1 de etic pull creases the resistance of the transmitted button 10. its a result of this variation of ourrent-flow, there results a cyclic variation of the resistance of the transmitter button corresponding to the variations in the currenp, which variations will have a periodicity equal to the natural frequency oi the structure and, in practice, this natural period is made approximately 1,000 cycles, at which frequency the ordinary telephone receiver is very eficient. The line wires L and L are connected respectively to the terminals 31 and 33; hence a circuit is formed from the positive pole of battery out on line Wire return on line wire L to terminal 31, thence through conductor 42 to transmitter button 11 and return by conductor 33 to terminal 32 to which the negative pole of battery 45 is connected. Since the transmitter button 11 is mounted in operable relation to the armature 17 a variation in resistance of this transmitter button takes place corresponding to the variation in resistance of the transmitter button 10 and the current flowing out over the line wires is varied accordingly. I Because of the very small current obtainable to operate this device and the high frequency at which it must operate, the armature must be very delicately adjusted in relation to the pole pieces and, in order to overcome any slight variation in the armatures, it has been found advantageous to give the armature a slight curvature 'so that .a-convex surface is presented to the pole pieces. A function of the spring 18 is to provide a flexible coupling as well as an electrical conductor between the buttons 10 and 11. If the armature 1'? is rigidly connected to the stems 1e and 15, it is almost impossible to adjust the nuts 16 in such a way as not to cause binding at one or other of the buttons, resulting in very unsatisfactory operation of the vibrator. The operation of the device is improved by the use of the condenser l? which is connected in parallel with the coils 23.23 and serves to steady the vibration of the device.

What is claimed is:

1. vibrator comprising an electromagnet having a winding, an armature therefor, a plurality of variable resistance elements upon which said armature is supported, one of said elements being connected in series with the winding of the electromagnet.

2. A vibrator comprising an electromaguet having a winding, an armature therefor, a plurality of variable resistance elements upon which said armature is flexibly mounted, one of said elements being in "series electrically with the winding of the electromag net.

A vibrator comprising an electromaghaving winding, an armature therefor, plural of variable resistance elements having stem portions extending through suitable perforations in said armature, stops on said stems to limit the movement of the armature in one direction, and a spring member secured to said armature and pressing a ainst the resistance elements. 7

4;. vibrator comprising an electromagnet having a winding, an armature therefor having a curved surface and a plurality of variable resistance elements upon which said armature is so supported as to present a convex surface to the electromagnet, one of said elements being connected in series with the winding of the electromagnet.

5. A vibrator comprising an electromagnet having a Winding, an armature therefor, a variable resistance element in operable relation with said armature and in series with the winding of the electromagnet, and a second variable resistance element so mounted with respect to the armature as to cause its resistance to vary in a mannercorresponding to the variation in resistance of said first element.

In witness whereof I my name this 27th day of December, A. D.

JOSEPH G. FIELD.

hereunto subscribe 25 

